This papercraft is Snork, one of the most recognizable mutants in the S.T.A.L.K.E.R. series appearing in all three games, the paper model is created by Alexander Protopopov. Thought to result from broken-minded soldiers left to "guard" the Zone, Snorks are recognized by the loud grunting they constantly produce. On some occasions, Snorks have also been seen talking to each other, although the "language" they use is barely recognizable.
The Snork is a horrifically mutated human soldier or Stalker, still wearing tattered remains of his uniform, boots and a GP-5 gas mask with cracked eyepieces, and a flailing hose. Exposure to radiation and anomalies in the wake of the second Chernobyl disaster has destroyed the human mind, leaving a feral, vicious beast psyche in its place and twisted the body, creating a dangerous predator.
Snorks were first encountered on May 22, 2007, near one of the army posts at the 30th kilometer of the Zone, on the Kharkov side. An officer waiting for his shiftman's car near the posts gate was attacked by a snork, which slaughtered him with rusty remains of a Izh 91 shotgun. The mutant was promptly gunned down by other soldiers. [Source: wikia]
You may download this papercraft template here: S.T.A.L.K.E.R.: Shadow of Chernobyl - Snork Free Papercraft Download